This invention relates to a novel lubricant additive acting as a viscosity index improver (VII) and imparting enhanced fuel economy when employed in a lubricating oil composition.
The addition of oligomeric waxes or oils of polytetrafluoroethylene (PTFE) to lubricating oils is designed to reduce wear and friction on mechanized components of internal combustion engines. Less frequent replacement of worn or damaged engine components and greater gasoline efficiency are direct consequences. PTFE oils or waxes are not, however, soluble in any known lubricating oil.
Thus, it is an object of the present invention to provide a method of enhancing fuel economy in internal combustion engines by chemically incorporating oligomeric perfluoroaliphatic grafts onto ethylene-propylene copolymers or ethylene-propylene terpolymers. By incorporating these perfluoroaliphatic appendages, the ethylene-propylene copolymers or ethylene-propylene terpolymers are soluble in lubricating oils.